[PATCH] media: rkvdec: fix v4l2-compliance failure

[Tharit Tangkijwanichakul <tharitt97@gmail.com>]

rkvdec fails v4l2-compliance in two tests related to
V4L2_CID_STATELESS_HEVC_SPS. The Control ioctls test reads the control
with GET_EXT_CTRLS and writes the same value back; TRY_EXT_CTRLS then
returns -EINVAL because the VDPU38x rkvdec_hevc_validate_sps() rejects
sps->chroma_format_idc == 0, which is the value returned when the
control has no default.

    v4l2-compliance 1.33.0-5491, 64 bits, 64-bit time_t
    v4l2-compliance SHA: b32589c51481 2026-07-16 08:51:38
    Control ioctls:
        fail: v4l2-test-controls.cpp(942):
	try_ext_ctrls returned an error (22)
      test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL
    Buffer ioctls:
        fail: v4l2-test-buffers.cpp(3102): node->streamon(q.g_type())
        fail: v4l2-test-buffers.cpp(3157): testBlockingDQBuf(node, m2m_q)
      test blocking wait: FAIL

Provide a control default via p_def with chroma_format_idc = 1 (4:2:0),
which is the only value the VDPU38x SPS validation accepts.
This fixes both the Control ioctls and the Buffer ioctls failures.

Tested on Radxa Rock 5B (RK3588).

Fixes: c9a59dc2acc7 ("media: rkvdec: Add HEVC support for the VDPU381 variant")
Signed-off-by: Tharit Tangkijwanichakul <tharitt97@gmail.com>
---
 drivers/media/platform/rockchip/rkvdec/rkvdec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/rockchip/rkvdec/rkvdec.c b/drivers/media/platform/rockchip/rkvdec/rkvdec.c
index 1d1e9bfef8e9..37603f049788 100644
--- a/drivers/media/platform/rockchip/rkvdec/rkvdec.c
+++ b/drivers/media/platform/rockchip/rkvdec/rkvdec.c
@@ -236,6 +236,10 @@ static const struct rkvdec_ctrls rkvdec_hevc_ctrls = {
 	.num_ctrls = ARRAY_SIZE(rkvdec_hevc_ctrl_descs),
 };
 
+static struct v4l2_ctrl_hevc_sps vdpu38x_hevc_sps_default = {
+	.chroma_format_idc = 1,
+};
+
 static const struct rkvdec_ctrl_desc vdpu38x_hevc_ctrl_descs[] = {
 	{
 		.cfg.id = V4L2_CID_STATELESS_HEVC_DECODE_PARAMS,
@@ -243,6 +247,7 @@ static const struct rkvdec_ctrl_desc vdpu38x_hevc_ctrl_descs[] = {
 	{
 		.cfg.id = V4L2_CID_STATELESS_HEVC_SPS,
 		.cfg.ops = &rkvdec_ctrl_ops,
+		.cfg.p_def.p_hevc_sps = &vdpu38x_hevc_sps_default,
 	},
 	{
 		.cfg.id = V4L2_CID_STATELESS_HEVC_PPS,
-- 
2.47.3